9QQ5
Mini-bacterioferritin from Candidatus Methanoperedens species BLZ2 in a partially oxidized state
Summary for 9QQ5
| Entry DOI | 10.2210/pdb9qq5/pdb |
| Descriptor | Bacterioferritin, FE (III) ION, 1,3,5,8-TETRAMETHYL-PORPHINE-2,4,6,7-TETRAPROPIONIC ACID FERROUS COMPLEX, ... (4 entities in total) |
| Functional Keywords | ferritin-like protein, mini-ferritin, fe-coproporphyrin iii, anaerobic methane-oxidising archaea, archaea, iron homeostasis, iron storage, dodecamer, nano-compartment, oxidoreductase |
| Biological source | Candidatus Methanoperedens sp. BLZ2 |
| Total number of polymer chains | 4 |
| Total formula weight | 67604.12 |
| Authors | |
| Primary citation | Wissink, M.,Engilberge, S.,Leao, P.,Jansen, R.S.,Jetten, M.S.M.,Belhamri, M.,Lemaire, O.N.,Royant, A.,Welte, C.U.,Wagner, T. Mini-bacterioferritins: structural insight into a ferritin-like protein from the anaerobic methane-oxidising archaeon Candidatus Methanoperedens carboxydivorans. Commun Biol, 2026 Cited by PubMed Abstract: Ferritins are ubiquitous among life forms, as they are essential for iron homeostasis. Here, we unveiled a novel member of the ferritin family, baptised mini-bacterioferritin. The characterised mini-bacterioferritin was isolated from a microbial enrichment dominated by the methanotrophic archaeon 'Candidatus Methanoperedens carboxydivorans'. Its atomic resolution crystal structure reveals a 12-mer assembly with a diiron ferroxidase centre located within a four-helix bundle. Redox-cycling experiments on protein crystals reveal a shift in iron position at the active site, which follows the established ferritin catalytic cycle. The 12-mer sphere-like structure harboured six Fe-coproporphyrin III ligands, positioned at the interdimeric interface, a characteristic previously only found in 24-mer bacterioferritins. Phylogenetics, together with structure predictions of closely related proteins, revealed that mini-bacterioferritins form a distinct clade within the ferritin family that might conserve ancestral traits. Future research will need to investigate the physiological roles of these enzymes, which were unsuspectingly widely distributed among prokaryotes. PubMed: 41865068DOI: 10.1038/s42003-026-09796-4 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.54 Å) |
Structure validation
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